Why is glucose so important? Well first off, it is the only currency that your brain cells can use. The brain has a special barrier (kinda like a giant force field) that limits access. In other words, you have to be a “VIP” to get in. Glucose is one molecule that gets this special treatment because the brain and nervous system in general needs a lot of energy. Thinking, learning, moving (including exercising), remembering, sensory sensations…all these things are fueled with glucose.
So does that mean I should eat sugar to improve brain function? Not necessarily. Before you run down to the convenience store and grab a bag of swedish berries, remember that you don’t need to eat sugar to give your body glucose. Huh?
While it’s true that glucose is a type of sugar, your body is able to make glucose from many different sources, including your fat stores, your muscles, and fat and protein that you eat. The key word here is GLUCONEOGENESIS which is a complicated way of saying “making new glucose molecules”.
I will spare you the dork details and tell you what you want to know.
- If you aren’t supplying your body with many carbohydrates (potatoes, bread, pasta, fruit, candy, etc) then you force it to make glucose from something else.This includes your fat stores (muffin top/love handles/arm flab, etc) but also your lean muscle mass. We want to keep our muscle and just lose the flab, so that’s one reason it’s so important to eat lean protein throughout the day if you are aiming for fat loss.
- You still need to have calorie balance. Just because you are eating low-carb doesn’t give you permission to eat bacon burgers with cheese all day. If you eat more calories than you need, you will store the extra calories for later. On the other hand, if you don’t eat enough calories, you will be a grumpy troll and your workouts will suck lemons.
- Exercise promotes GLUCONEOGENSIS! Your muscles are divas when it comes to their glucose supply. They want it yesterday! That’s why your body stores some glucose right in the muscle cells so that it’s ready-to-use. When you exercise, your muscles use up this energy and it has to be replaced. If you are trying to increase muscle mass or promote recovery, giving your body a good dose of sugar and protein after your workout is just the ticket! If, on the other hand, you want to lose fat, limit the carbs after exercise and force your body to convert stored fat into glucose (= fat loss!). To prevent muscle loss, don’t forget to have some protein though!
- You may feel a little loopy/foggy/tired for the first week or so on a low-carb diet. Back to the part about the brain needing glucose to do stuff. The easiest way to get glucose is from carbohydrates. It takes more work to break down fats as an energy source, which is part of the reason you may feel tired, grumpy, and a little dumber when you first start a low-carb diet. Choose your timing wisely and be patient with yourself. Also make sure that you are getting enough calories including healthy fats and lots of veggies, and that you sleep enough 😀 A greens supplement is also a good idea to ensure you are getting the nutrients you need.
- Performance is going to suck. If you are looking to improve strength, size, power, or endurance, stay away from a low-carb diet! Carbohydrates are really important for improving performance and promoting recovery. Low-carb diets are best for those who want to change their body composition and how they look.
- Time Limits & Cycling. A diet consisting primarily of fat, protein, and vegetables is unbalanced and shouldn’t be followed for more than 3-4 months at a time with a specific goal in mind. Building in high-carb, high-calorie days are also important so that you prevent burnout, nutritional deficiencies, and keep your sanity!
- Finally, it is important to recognize that low-carb diets aren’t the only strategy for fat loss and they certainly aren’t for everyone! Start by eating more veggies and lean proteins. Switch your carbs from chips and pizza to potatoes and oatmeal. Drink more water. And of course, be more active!